WO2007105366A1

WO2007105366A1 - Rotation angle detector and bearing with rotation detector

Info

Publication number: WO2007105366A1
Application number: PCT/JP2007/000180
Authority: WO
Inventors: Toru Takahashi
Original assignee: Ntn Corporation
Priority date: 2006-03-14
Filing date: 2007-03-07
Publication date: 2007-09-20
Also published as: EP2006640B1; US20100225307A1; EP2006640A2; US7928725B2; EP2006640A4; EP2006640A9

Abstract

Provided are a rotation angle detector having no error caused by time lag and providing accurate rotation angle information at each time instant, and a bearing incorporating the rotation angle detector. A rotation side member is provided with a magnet (2) having circumferential anisotropy about the center of rotation of the rotation side member. A magnetic sensor (5) where magnetic sensor elements are planarly arranged is placed on a stationary side member so as to face the magnet (2) in the axial direction of the center of rotation of the rotation side member. The rotation angle detector further has angle calculation means (6) and delay time correction means (7). The angle calculation means (6) measures the magnetic field strength of the magnet (2) based on an output of each magnetic sensor element of the magnetic sensor (5) and detects the rotation angle of the rotation side member based on the measurement. The delay time correction means (7) corrects a delay time after the magnetic field of the magnet (2) is detected by the magnetic sensor element until a detection angle is outputted from the angle calculation means (6).

Description

Specification

Rotation angle detection device and bearing with rotation detection device

Technical field

The present invention relates to a rotation angle detection device used for rotation angle detection in various devices, for example, rotation angle detection for rotation control of a small motor, and a bearing with a detection device incorporating the rotation detection device. .

Background art

[0002] As a rotation angle detection device that can be incorporated into a small device and can detect a rotation angle with high accuracy, a device using a magnetic sensor array has been proposed (for example, Japanese Patent Laid-Open No. 2000-03-3). 7 1 3 3). As shown in Fig. 22, the sensor chip is composed of a magnetic sensor array 45 consisting of a large number of magnetic sensor elements (MAGFETs) arranged together with a circuit 46 such as a signal amplification circuit, AD conversion circuit, and digital signal processing circuit. The sensor chip 42 is integrated in the 42 and is disposed so as to face the magnet 44 disposed on the rotation side member 41. In this case, the magnet 44 has a circumferential anisotropy around the rotation center O, and on the sensor chip 42, the magnetic sensor array 4 along each side of the four sides of the virtual rectangle. 5 is placed.

In the rotation angle detection device 43 configured in this way, the output of the magnetic sensor array 45 on each side is read by the signal amplification circuit and AD conversion circuit to detect the magnetic field distribution of the magnet 44, and the detection result Based on the above, the rotation angle of the magnet 44 is calculated by the digital signal processing circuit.

[0003] Although the detection method is different from the rotation angle detection device 43 disclosed in the above publication, a plurality of magnetic sensor elements such as Hall elements are used, and the output signals are calculated to fix the rotation angle detection apparatus 43 to the rotating body. Rotation detectors (such as AMS rotary encoder LSI) that detect the position and movement of magnets have also been proposed.

[0004] In these rotational angle detection devices, signals of individual magnetic sensor elements are read out. Time and calculation processing time for obtaining information such as the rotation angle from the read signal are required, and a time delay of the detection signal occurs. For this reason, when the rotation speed of the rotation side member is high, there is a difference between the actual rotation speed and the detected rotation angle, and there is a problem that it is difficult to use in applications that require detailed rotation position information in real time. It was. That is, in the operation of the rotation angle detection device having the above configuration, the cycle of magnetic field measurement → angle calculation → angle output is repeated, and therefore angle data is output at a constant time interval corresponding to the cycle. For this reason, the output angle data has a time delay corresponding to the time required for angle calculation, and there is a problem that accurate angle information at the observation time cannot be obtained. In addition, it is difficult to accurately detect the rotation angle and rotation speed at an arbitrary time when controlling the rotation of the motor by detecting the rotation angle and rotation speed using this rotation angle detection device. There were also challenges.

Disclosure of the invention

[0005] An object of the present invention is to provide a rotation angle detection device capable of obtaining accurate rotation angle information at each time without an error due to time delay, and a bearing with a detection device incorporating the rotation angle detection device. In addition, the present invention provides a rotation angle detection device that can accurately detect a rotation angle at an arbitrary time by detecting the angle of a rotation shaft such as a motor, and a bearing with a detection device incorporating the rotation angle detection device. That is.

[0006] A rotation angle detection device of the present invention is provided with a magnet provided on a rotation side member and having circumferential anisotropy around the rotation center, and opposed to the magnet in the axial direction of the rotation center of the rotation side member. The magnetic field strength of the magnet is measured from the output of each magnetic sensor element of the magnetic sensor and the plurality of magnetic sensor elements arranged in a plane on the fixed side member, and the rotation side is based on the measured value. A rotation angle detection device comprising an angle calculation means for detecting a rotation angle of a member, wherein a delay from when the magnetic field of the magnet is detected by a magnetic sensor element until the detection angle is output by the angle calculation means. Delay time correcting means for correcting the extended time. The magnetic sensor is, for example, a magnetic sensor array, but a magnetic sensor such as a plurality of Hall elements. It may be a rotary encoder that uses a sensor and calculates the angle from these output signals. Here, the magnetic generation means “having circumferential anisotropy” means that the strength of the magnetic field changes in the circumferential direction. As a result, when the magnetism generating means rotates with the rotating wheel, the magnetic field at a fixed point outside the magnetism generating means fluctuates at a period corresponding to the rotation speed.

According to this configuration, the detection angle output from the angle calculation means is determined by the delay time correction means by the time delay from when the magnetic field of the magnet is detected by the magnetic sensor element until the detection angle is output by the angle calculation means. Since the correction is made, the output angle information is very close to the actual rotation angle of the rotation side member, and accurate angle information can be obtained in real time.

[0007] In the present invention, the magnet may be disposed, for example, at a rotation axis end portion of the rotation side member to constitute a pair of magnetic poles.

[0008] In the present invention, interpolation means for calculating a change in angle by interpolating a magnetic field sampling interval by the magnetic sensor, delay time correction by the delay time correction means, and interpolation processing by the interpolation means are performed. Output means for outputting the rotation angle may be provided. Since the interpolation means calculates the change in the rotation angle by interpolating the magnetic field sampling interval, the high-speed rotation operation of the rotating side member can be detected more finely than the sampling time interval. As a result, there is no error due to time delay, and accurate rotation angle information at each time can be obtained.

In the present invention, a pulse generation circuit that generates a rotation pulse signal from the output of the magnetic sensor may be provided, and the output means may output a rotation angle output as a pulse signal. Further, the pulse signal may be composed of two rotation pulse signals having a 90 ° phase difference, or a rotation pulse signal and a rotation direction signal. In the case of this configuration, the rotation direction of the rotation side member can also be determined.

[0010] In the present invention, an index generation circuit that outputs an index signal for each rotation of the rotating side member from the output of the magnetic sensor may be provided. . In this configuration, absolute rotation angle information can also be obtained in real time by counting pulses.

[001 1] In the present invention, a storage means for storing an angle value for outputting an index signal may be provided, and an angle value setting means for setting an angle value for outputting the index signal may be provided. As a result, an index signal generated at an arbitrary angle can be obtained in a state in which the delay of the calculation time is compensated. The angle value setting means may be composed of a communication circuit.

[001 2] In the present invention, function on / off means for switching the functions of the delay time correcting means and the interpolation means between an on state and an off state may be provided. In addition, there is provided an automatic switching means for switching between the ON state and the OFF state of the delay time correction means depending on whether the rotation speed of the rotation side member is equal to or higher than the set speed, and the OFF state is set when the rotation speed is less than the set speed. It is good also as what. The angle value setting means may be composed of a communication circuit.

When the rotational speed of the rotation side member is low, the influence of the delay time in the angle calculation means is small, and therefore a stable detection result may be obtained if the delay time compensation process is not performed by the delay time correction means. . Therefore, in such a case, if the function to turn on / off the delay correction function automatically according to the rotation speed by the function on / off means, the delay time compensation process by the delay time correction means can be omitted and stable. The detected result can be obtained.

[001 3] In the present invention, the delay time correcting means includes a rotational speed calculating means for calculating a rotational speed from a temporal change in the rotational angle detected by the angle calculating means, and a rotation calculated by the rotational speed calculating means. You may have an angle time delay correction | amendment means which correct | amends the time delay of the rotation angle from the detection of the magnetic field by the said magnetic sensor until a rotation angle is output by the said angle calculation means by speed. The output of the angle calculation means for detecting the rotation angle of the rotating shaft from the output of the magnetic sensor has a time delay from the time when the magnetic sensor samples the magnetic field of the magnet to the time when the rotation angle is calculated and output. Therefore, the actual rotation angle of the rotation axis when reading the rotation angle data may be different from the read data. Therefore, the angle calculation Based on the rotation speed calculated by the rotation speed calculation means from the time change of the rotation angle detected by the means, the rotation speed calculation means corrects the time delay of the rotation angle detected by the angle calculation means. This makes it possible to detect the exact rotation angle of the rotation shaft.

[0014] In the present invention, the rotation angle corrected by the angle time delay correction unit is obtained every fixed time, the rotation angle information for each fixed time and the rotation speed information calculated by the rotation speed calculation unit, Therefore, a rotation angle estimation means for estimating the rotation angle of the rotation shaft at an arbitrary time may be provided.

Since the rotation angle data corrected by the angle time delay correcting means is discrete data output at a constant time interval, angle information cannot be obtained more finely than the interval at which the data is updated. Therefore, the rotation angle estimation means estimates the angle value at the time when the rotation angle data is requested from the rotation angle data and the rotation speed, and estimates the rotation angle at an arbitrary time. As a result, the rotation angle at an arbitrary time can be accurately detected.

[001 5] In this invention, the angular calculation means, the rotation speed calculation means, and the angular time delay correction means may be integrated in a large-scale integrated circuit constituting the magnetic sensor. In this configuration, the rotation angle data output from the semiconductor chip on which the large-scale integrated circuit is integrated indicates the rotation angle at that time. Therefore, the rotation angle detection device can be made easier to handle.

[001 6] A bearing with a detection device according to the present invention is obtained by incorporating the rotation angle detection device according to the present invention into a bearing in which a rolling element is interposed between the rotation side member and the fixed side member. is there. According to this configuration, it is possible to reduce the number of parts, the number of assembly steps, and the size of the equipment using the bearing.

[001 7] A motor rotation control device according to the present invention includes a rotation angle detection device according to the present invention, a control circuit that controls the excitation current and the excitation timing of the motor based on the output of the rotation angle of the rotation angle detection device, and It is equipped with. According to this configuration, the rotation control of the motor can be performed with high accuracy. In particular, the rotation angle estimation If a measuring means is provided, the magnetic pole position of the motor at any time can be known accurately, so the excitation timing is controlled in order to increase the motor efficiency and keep the rotational noise low. In some cases, fine control according to the rotation speed and the rotation angle of the rotor is effective. In this case, high-precision angle detection is possible with a small rotation angle detection device, and the device can be downsized and improved in performance.

[0018] The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and description, and should not be used to define the scope of the present invention. The scope of the invention is defined only by the appended claims. In the accompanying drawings, the same part number in multiple drawings indicates the same part.

FIG. 1 is a sectional view of a bearing with a detection device incorporating a rotation angle detection device according to a first embodiment of the present invention.

FIG. 2 is an enlarged side view showing a rotation angle detection device installation portion in the bearing.

FIG. 3 is a plan view of a semiconductor chip constituting an example of a rotation sensor in the bearing.

FIG. 4 is an explanatory diagram of an angle calculation process by an angle calculation unit of the rotation sensor.

FIG. 5 is a waveform diagram showing an output of a magnetic sensor array in the rotation sensor.

FIG. 6 is a block diagram showing a schematic configuration of the rotation angle detection device.

FIG. 7 is a block diagram showing a detailed configuration of a delay time correction unit and an interpolation unit in the rotation angle detection device.

FIG. 8 is a block diagram showing a detailed configuration of output means in the rotation angle detection device.

FIG. 9 is an explanatory view showing a processing operation of a delay time correcting means in the rotation angle detecting device.

[Figure 10] AB phase signal output from output means in the same rotation angle detector FIG.

FIG. 11 is a block diagram showing a schematic configuration of a rotation angle detection device according to a second embodiment of the present invention.

FIG. 12 is a plan view of a semiconductor chip constituting an example of a rotation sensor in a bearing with a detection device incorporating a rotation angle detection device according to a third embodiment of the present invention.

FIG. 13 is a timing chart showing a cycle of processing operations in which the rotation sensor detects and outputs a rotation angle.

FIG. 14 is a block diagram showing a part of the circuit configuration of the rotation sensor.

FIG. 15 is a block diagram showing rotation angle estimation means in the rotation sensor.

FIG. 16 is an explanatory view showing the processing operation of the rotation angle estimating means.

FIG. 17 is a block diagram showing a schematic configuration of an example of a motor drive device incorporating a rotation angle detection device.

FIG. 18 is a cross-sectional view of an example of a brushless motor incorporating a rotation angle detection device.

FIG. 19 is a partially enlarged cross-sectional view of another example of a brushless motor incorporating a rotation angle detection device.

FIG. 20 is a block diagram showing a circuit configuration of the rotation sensor according to an application example of the present invention.

FIG. 21 is a block diagram showing details of the output circuit in FIG.

FIG. 22 is a perspective view of a conventional example.

BEST MODE FOR CARRYING OUT THE INVENTION

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a cross-sectional view of a bearing incorporating the rotation detection device of the first embodiment. This bearing 20 with a detecting device is a rolling bearing in which a rolling element 24 held by a cage 23 is interposed between rolling surfaces of an inner ring 21 and an outer ring 22. The rolling element 24 is composed of a pole, and this rolling bearing 20 is a single row deep groove ball bearing. The inner ring 2 1 is fitted with the rotary shaft 10 that is a rotating side member in a press-fit state, and the outer ring 2 2 is a bearing. It is installed in the equipment housing (not shown).

[0021] The rotation detection device 1 incorporated in the rolling bearing 20 is an inner ring of the rolling bearing 20

2 Provided with a magnet 2 arranged on the 1 side and a rotation sensor 3 arranged on the outer ring 2 2 side. Specifically, a permanent magnet 2 having a pair of magnetic poles N and S is arranged on a rotating shaft 10 that rotates together with the inner ring 2 1, and rotates to a sensor mounting member 27 that is in a fixed relationship with the outer ring 2 2. Sensor 3 is arranged.

As shown in FIG. 2, the magnet 2 has a direction in which the magnetism generated from the pair of magnetic poles N and S is around the axis O of the rolling bearing 20. This magnet 2 is fixed to the center of the end of the rotary shaft 10 so that the axis O of the rolling bearing 20 coincides with the center of the magnet 2. As the magnet 2 rotates together with the rotary shaft 10, the N magnetic pole and the S magnetic pole pivot around the bearing axis O.

The rotation sensor 3 is a sensor that senses the magnetism of the magnet 2 and outputs information on the rotation angle. The rotation sensor 3 is attached to the outer ring 22 side via the sensor attachment member 27 so as to face the magnet 2 in the axial direction of the axis O of the rolling bearing 20. Specifically, the sensor attachment member 27 is attached to the outer ring 22, and the rotation sensor 3 is fixed to the sensor attachment member 27. The sensor mounting member 27 has an outer peripheral cylindrical portion 2 7 a fitted to the inner surface of the outer ring 22 2, and a flange portion 2 7 b formed in the vicinity of the distal cylindrical portion 2 7 a is connected to the outer ring 22 2. Positioned in the axial direction by engaging the width surface. An output cable 29 for taking out the output of the rotation sensor 3 is also attached to the sensor attachment member 27.

As shown in a plan view in FIG. 3, the rotation sensor 3 is configured by integrating a large scale integrated circuit (LSI) on one semiconductor chip 4. The large-scale integrated circuit measures the magnetic field strength of the magnet 2 from the plurality of magnetic sensor elements 5a constituting the magnetic sensor 5 and the output of the magnetic sensor element 5a, and based on the measured value, An angle calculation means 6 for detecting a rotation angle of a certain rotating shaft 10, a delay time correction means 7, an interpolation means 8, and an output means 9 are included. In FIG. 3, the angle calculation means 6, the delay time correction means 7, the interpolation means 8, and the output means 9 are conceptually shown in blocks, and the shapes and dimensions of these means 6 to 9 are shown. It does not indicate the law. On the semiconductor chip 4, the magnetic sensor elements 5 a are arranged along the four sides on the virtual rectangle to form the four-side magnetic sensor arrays 5 A to 5 D. In this case, the center O ′ of the rectangle coincides with the axis O of the rolling bearing 20. The four-side magnetic sensor arrays 5A to 5D may be ones in which the sensor elements 5a are arranged in a line in the example of the figure. . An arithmetic circuit unit including the angle calculating unit 6, the delay time correcting unit 7, the interpolating unit 8, the output unit 9, and the like is arranged inside the rectangular arrangement of the magnetic sensor arrays 5A to 5D. The semiconductor chip 4 is fixed to the sensor mounting member 27 so that the element formation surface faces the magnet 2.

As described above, the magnetic sensor element 5 a and the arithmetic circuit unit (angle calculation means 6, delay time correction means 7, interpolation means 8, output means 9) are integrated and integrated on the same semiconductor chip 4. This eliminates the need for wiring between the magnetic sensor element 5a and the arithmetic circuit section, enables the rotation sensor 3 to be made compact, improves the reliability against breakage, and facilitates the assembly work of the rotation detection device 1. In particular, the chip size can be further reduced by arranging the arithmetic circuit section inside the magnetic sensor arrays 5 A to 5 D arranged in a rectangular shape as described above.

FIG. 4 and FIG. 5 are explanatory diagrams of the rotation angle calculation processing by the angle calculation means 6. Figures 5 (A) to (D) show the output waveform diagrams of the magnetic sensor arrays 5A to 5D when the rotary shaft 10 is rotating. The horizontal axes of the magnetic sensor arrays 5A to 5 The magnetic sensor element 5a in D is shown, and the vertical axis shows the intensity of the detected magnetic field.

Now, assume that the positions X 1 and X 2 shown in FIG. In this state, the outputs of the magnetic sensor arrays 5A to 5D have signal waveforms shown in FIGS. 5 (A) to (D). Therefore, the zero cross positions X 1 and X 2 can be calculated by linear approximation from the outputs of the magnetic sensor arrays 5 A and 5 C.

The angle calculation can be performed by the following equation (1). θ = tan " ¹ (2 LZb) ...... (1)

Here, 0 is a value indicating the rotation angle of the magnet 2 as an absolute angle (absolute value). 2 L is the length of one side of a quadrangle composed of the magnetic sensor arrays 5 A to 5 D arranged in a rectangle. b is the lateral length between the zero cross positions X 1 and X 2.

When the zero cross positions X 1 and X 2 are in the magnetic sensor arrays 5 B and 5 D, the rotation angle 0 is calculated in the same manner as described above based on the zero cross position data obtained from the outputs.

By the way, there is a time delay until the angle calculation means 6 performs the above calculation and outputs the rotation angle 0. Therefore, in the high speed rotation state, the detected rotation angle position may be different from the actual rotation angle position. Figure 9 shows the relationship between the detected angles 0 _n -1, θ _η , 0 _{η + 1} and the actual angles calculated and output by the angle calculation means 6 at times t ^, t _n , t _{n + 1} . Show. The difference between the detected angles 0, θ _η , θ _{η + 1} and the actual angle is due to the delay.

FIG. 6 is a block diagram showing a schematic configuration of the rotation detection device 1 according to the first embodiment. The delay time correcting means 7 is a means for correcting the detected angle S output from the angle calculating means 6 by the time delay. The delay time correction means 7 has a speed detection circuit 11, a target value calculation circuit 12, and a previous target value storage memory 13, as shown in FIG.

The speed detection circuit 1 1, the time in the detected angle theta _eta outputted from the angle calculating means 6, the time ΐ detected angle output from the angle calculating means 6 to _eta 0 ^ difference AS _n (= _{_θ} η -θ η -,) Is calculated as the rotation speed. This difference value Δ0 _η indicates the angle rotated at one magnetic field sampling interval Τ. Since the variation of the difference value Λ 0 _η increases, an averaging filter or the like may be used as necessary. The target value calculation circuit 1 2 uses the rotation speed (difference value Λ 0 _η ) detected by the speed detection circuit 1 ₁ to output the next sampling time (the angle calculation means 6 then outputs the detection angle 0 _{η + 1)} . ) Calculate the rotation angle position すべき_{η + 1} that should reach t _{n + 1} . Here, the target value calculation circuit 12 compensates the delay time until the detection angle output. So As a calculation method for the compensation, for example, the use of first-order approximation, t _{n +} rotational angular position P _{n + 1} to be reached to _1,

Ρ _{η + 1} = θ _η + α ■ Α θ _η …… (2)

It becomes. Here, it is a coefficient that compensates for the delay time, and is set according to the size of the delay time. In the case of Fig. 9, it is set to = 2. The next predicted detection angle ηη _{+ 1} determined in this way becomes the target value. When delay time compensation is performed in this way, ηη _{+ 1} becomes the position shown in Fig. 9, and the value close to the actual rotation angle position becomes the target value. At this time, the target value storage memory 1 3, the target value calculating circuit 1 2 force "target value previously calculated [rho _eta is stored.

The interpolating means 8 is a means for calculating a change in the rotation angle by interpolating the magnetic field sampling interval Τ. The interpolation means 8 has a pulse generation circuit 14 and a current position counter 15 as shown in FIG. Above the target value calculating circuit 1 2, Motoma' target value as described above [rho and _{eta + 1,} by using the previous target value stored in the target value storage memory 1 3 [rho _eta, next sampling time t Count amount C _n to be changed by _{n + 1} ,

C n = P n + 1— P n (^)

And input to the pulse generation circuit 14 of the interpolation means 8. Further, the target value calculation circuit 12 calculates the count amount C _n and then stores the current position A as P _n in the previous target value storage memory 13 again. Then, C _n clocks are sequentially input to the current position counter 15. As a result, the count value of the current position counter 15 changes, and the correction angle output (delay time compensation + interpolation) A is obtained.

The angle output signal A interpolated in this way is a digital signal, but always operates so that it changes only by one soil. Therefore, it is possible to generate a two-phase pulse signal such as AB phase used in a normal encoder from the lower two bits of the current position counter 15 count value (signal A).

For example, the lower two bits of the signal A are A O and A 1, and the A and B phase signals can be generated by the logic circuit shown in FIG.

[0029] Output means 9 includes delay time compensation by delay time correction means 7, and interpolation means. This is a means for outputting the rotation angle A that has been subjected to the interpolation processing by 8. The output unit 9 includes an index signal generation unit 16, an angle value storage unit 17, and an angle value setting unit 18 as shown in FIG. The output means 9 has a terminal for outputting the index signal Z every time the rotating shaft 10 as the rotation side member makes one rotation, in addition to a terminal for directly outputting the angle signal A from the interpolation means 8. The index signal generation means 16 outputs the index signal Z to the terminal when the count value (signal A) of the current position counter 15 in the interpolation means 8 becomes 0, for example. The angle value storage means 17 is a memory for storing an angle value for outputting the index signal Z, and the angle value setting means 18 is a means for setting an angle value to be stored in the angle value storage means 17. The angle value setting means 18 is constituted by a communication circuit, for example, and the angle value stored in the angle value storage means 17 can be variably set from the outside. Thus, when the count value (signal A) of the current position counter 15 in the interpolation means 8 becomes equal to the angle value stored in the angle value storage means 17, the output terminal of the index signal generation means 16 Index signal Z is output to Since signal A is a signal that has been subjected to delay time compensation and interpolation processing, an index signal with a small error from the actual angle can be output.

As described above, in the rotation detection device 1 according to the first embodiment, the detection angle 0 output from the angle calculation unit 6 is changed to the angle calculation unit 6 after the magnetic field of the magnet 2 is detected by the magnetic sensor element 5a. Since the delay time correction means 7 corrects by the time delay until the detection angle S is output, the output angle information is very close to the actual rotation angle of the rotating side member (rotating shaft 10). Value, and accurate angle information can be obtained in real time.

Also, since the interpolation means 8 interpolates the magnetic field sampling interval T and calculates the change in the rotation angle, the high-speed rotation operation of the rotating side member (rotating shaft 10) can be performed from the sampling time interval T. Can also be detected in detail. In the first embodiment, since the two-phase signal is generated from the angle signal A that is output after being interpolated by the interpolation means 8, the rotation is performed using these signals. The direction of rotation of the side member (rotating shaft 1 0) can also be determined.

In the first embodiment, since the index signal Z can also be output by the index generating means 16, absolute rotation angle information can be obtained in real time by counting pulses.

[0031] In addition, in the bearing 20 with the detecting device of FIG. 1, the rotation detecting device 1 is incorporated in the rolling bearing 20. Therefore, the number of parts of the bearing-using device, the number of assembly steps can be reduced, and the size can be reduced. be able to.

FIG. 11 shows a second embodiment of the present invention. The rotation detection device 1 of the second embodiment is provided with function on / off means 19 for selectively turning on / off the functions of the delay time correction means 7 and the interpolation means 8 in the previous embodiment shown in FIG. It is. Function on / off means 19 includes automatic switching means 30 and automatic switching speed setting means 31.

The automatic switching means 30 can delay time by turning on / off the switches 3 2 and 3 3, for example, depending on whether or not the rotation speed of the rotation side member (rotary shaft 10) is equal to or higher than the set rotation speed. This is a means for switching the function of the correction means 7 and the interpolation means 8 between the on state and the off state. Specifically, when the speed is less than the set rotational speed, the functions of the delay time correction means 7 and the interpolation means 8 are in the off state. Switch so that. In FIG. 11, the force delay time correcting means 7 and the interpolating means 8 are configured to turn on / off the external switches 3 2 and 3 3 of the delay time correcting means 7 and the interpolating means 8 for the sake of simplicity. The internal circuit operation may be switched.

The automatic switching speed setting means 31 is a means for variably setting the value of the set rotational speed at which the automatic switching means 30 performs automatic switching, and is constituted by a communication circuit, for example. In addition, the setting rotational speed value may be variably set, for example, by operating the switch terminal from the outside. Other configurations are the same as those in FIG. 6, and the description thereof is omitted here.

[0033] When the rotation speed of the rotation side member (rotary shaft 10) is low, the influence of the delay time in the angle calculation means 6 is small, so the delay time by the delay time correction means 7 A stable detection result may be obtained when the compensation process is not performed. In the rotation detection device 1 of this embodiment, the automatic switching means 30 of the function on / off means 19 automatically turns on / off delay correction according to the rotation speed. Thus, it is possible to obtain a stable detection result by omitting the delay time compensation processing by the delay time correction means 7.

When the function of the delay time correction means 7 is turned off, the angle calculation means 6 should be the rotation angle position P _n that should reach the next sampling time t _{n + 1} when the detection angle 0 _{n + 1} is output. ₊₁ is calculated as the following equation (2 ').

_{Η η + 1} = θ _η + Α Θ „…… (2 ')

FIG. 12 is a plan view of a semiconductor chip constituting an example of a rotation sensor 3 in a bearing with a detection device incorporating a rotation angle detection device according to a third embodiment of the present invention. Fig. 14 is a block diagram showing a part of the circuit configuration of the rotation sensor 3A. The rotation sensor 3 A in FIG. 12 is configured by integrating a large-scale integrated circuit (LSI) on one semiconductor chip 4, similarly to the rotation sensor 3 of the first embodiment. The large-scale integrated circuit includes a plurality of magnetic sensor elements 5a constituting the magnetic sensor 5, and an arithmetic circuit unit 6A that calculates and outputs a rotation angle from the output of the magnetic sensor element 5a. On the semiconductor chip 4, the magnetic sensor element 5 a is arranged along each of the four sides on the virtual rectangle to form four-side magnetic sensor arrays 5 A to 5 D. In this case, the center O ′ of the rectangle coincides with the axis O of the rolling bearing 20. Magnetic sensor array 5 A ~ 5 D of the four sides is the sensor element 5 a in the example of the figure it is assumed in a row, there is aligned parallel to the sensor element 5 _three "double row Also good. The arithmetic circuit unit 6A is arranged inside a rectangular arrangement of the magnetic sensor arrays 5A to 5D. The semiconductor chip 4 is fixed to the sensor mounting member 27 so that its element forming surface faces the magnet 2.

The arithmetic circuit unit 6 A has an angle calculation means 61, a rotation speed calculation means 6 2, an angle time delay correction means 6 3 (FIG. 14), and a rotation angle estimation means 64 (FIG. 15). To do. The angle calculation means 61 is used to calculate the rotation axis 10 from the output of the magnetic sensor 5. Calculate the rotation angle. The rotation speed calculation means 62 calculates the rotation speed from the time change of the rotation angle calculated by the angle calculation means 61, and also detects the rotation direction. The angle time delay correction means 63 corrects the time delay of the rotation angle from the detection of the magnetic field by the magnetic sensor 5 to the output of the rotation angle by the angle calculation means 61. The rotation angle estimation means 64 obtains the rotation angle corrected by the angle time delay means 63 at regular intervals, and the rotation angle information and the rotation speed calculation means 62 calculate at regular intervals. From the speed information, the rotation angle of the rotary shaft 10 at an arbitrary time is estimated.

FIG. 13 shows a cycle of a processing operation for detecting and outputting a force rotation angle 0 by a magnetic sensor circuit 50 (FIG. 14) composed of the magnetic sensor arrays 5 A to 5 D and the angle calculation means 6 1. Is a timing chart showing In the interval T a in the first half of the time T of the one cycle, the magnetic sensor array 5 A to 5 D, which is the magnetic sensor 5 of the rotation sensor 3 A, samples the magnetic field of the magnet 2 on the rotation side, and the latter half of the one cycle. In the section Tb, the angle calculation means 61 calculates the rotation angle S from the sampled value and outputs it. As described above, since there is a time delay until the angle data is calculated, the actual rotation angle of the rotation axis 10 when the rotation angle data is read may be different from the read data. .

[0037] The rotation speed calculation means 6 2 (Fig. 14) in the arithmetic circuit section 6A is the amount of change from the data of the rotation angle S output from the angle calculation means 61 at every time T as described above. Is calculated to calculate the rotational speed ω of the rotating shaft 10.

Magnetic data obtained by each sampling by the magnetic sensor arrays 5 A to 5 D in FIG. 14 is amplified and A / D converted and input to the angle calculation means 61. The angle calculation means 6 1 performs the arithmetic processing shown in FIGS. 4 and 5 based on the sampling values of the magnetic sensor arrays 5 A to 5 D every time, and calculates the rotation angle 0 each time according to the equation (1). calculate.

On the other hand, the rotation speed calculation means 6 2 is calculated from the amount of change in the rotation angle data 0 output from the angle calculation means 61 every time T and the elapsed time T obtained by the timer 65. Rotation speed ω and rotation direction are calculated. Rotational speed The calculation of the degree ω is performed as follows, for example.

Assuming that the rotation angle 0 (η) sampled every time is changing, the rotation speed ω can be obtained from the angle change between consecutive samplings as shown in the following equation (4).

ω = {θ (η + 1)-θ (η)} …… …… (4)

However, 0 (η) and θ (η + 1) represent the rotation angles obtained in the η-th and (η + 1) -th sampling.

Based on the rotation speed ω data obtained in this way and the elapsed time obtained by the timer 65, the angle time delay correction means 63 corrects the rotation angle 0 calculated by the angle calculation means 61. That is, the angle time delay correction means 63 calculates the rotation angle 0 (η) when the rotation shaft 10 is rotating at the rotation speed ω calculated by the rotation speed calculation means 62. It can be estimated by the following equation (5) how much the rotation angle 0 has changed during the time Tb required for this.

Θ (n + T b) = θ (η) + ω x T b ...... (5)

However, 0 (n + Tb) is the rotation angle at the time when the calculation by the angle calculation means 7 is completed from the n-th sampling.

Since this rotation angle detection device 1 is configured to detect the rotation of the magnet 2 provided at the shaft end of the rotation shaft 10 by the rotation sensor 3, the rotation speed is detected by the inertia of the rotation shaft 10 which is a rotating body. ω is in a state in which rapid fluctuations are unlikely to occur, and with the above-described rotation angle correction, it is possible to estimate a rotation angle with considerably high accuracy.

Here, as a part of a large-scale integrated circuit integrated on the semiconductor chip 4, the rotation speed calculation means 62 and the angle time delay correction means 63 are provided together with the angle calculation means 61. Therefore, the rotation angle 0 data output from the semiconductor chip 4 indicates the rotation angle at that time, and a rotation angle detection device that is easier to handle for control in various devices that operate by receiving this data. 1

The rotational speed calculating means 62 and the angle time delay correcting means 63 are semiconductors. It may be provided separately from the chip 4.

FIG. 15 is a block diagram showing the configuration of the rotation angle estimation means 64 in the arithmetic circuit section 6A. In the figure, a rotation angle detection circuit 60 indicates a circuit unit including the angle calculation means 61, the rotation speed calculation means 62, the timer 65, and the angle time delay correction means 63 in FIG. . Since the rotation angle data 0 obtained by the rotation angle detection circuit 60 0 after the time delay correction is discrete data output at intervals of the fixed time T as described above, the rotation angle data 0 is larger than the interval at which the data is updated. Detailed angle information cannot be obtained.

Therefore, the rotation angle estimation means 6 4 predicts and interpolates the angle value at the time when the rotation angle data is requested from the rotation angle data 0 and the rotation speed ω, and includes a timer 6 6, a memory 6 7 and Includes angle data interpolation circuit 6 8. Specifically, as shown in FIG. 16, the angle data interpolation processing circuit 68 of the rotation angle estimation means 64 has the latest rotation angle data (for example, 0 2) output from the rotation angle detection circuit 60. The elapsed time Δ t from the output time t 2 until the request trigger a is received is measured by the timer 66, and the angle change amount predicted from the rotational speed ω is added to the data. That is, the angle data interpolation processing circuit 68 once stores the rotation angle data 0, the rotation speed ω, and the elapsed time in the memory 67, and calculates the rotation angle S when the request trigger signal a is received from these values. Predict. As a result, the rotation angle data S 2 + ΔΘ at time t 2 + Δt when the request trigger a is input can be output from the angle data interpolation processing circuit 68. In other words, the rotation angle at an arbitrary time can be accurately detected and output even when the rotating shaft 10 is rotating or at rest. The rotation angle 0 calculated by the arithmetic circuit unit 6 A is output by the output cable 29 (FIG. 1).

Here, as part of a large-scale integrated circuit integrated on the semiconductor chip 4, together with the angle calculation means 61, the rotation speed calculation means 62, and the angle time delay correction means 63 in FIG. Since the rotation angle estimation means 64 is provided, a small and highly accurate rotation that can obtain accurate rotation angle information at an arbitrary time. The sensor 3 A is configured, and a compact rotation angle detector 1 can be realized.

The rotation angle estimating means 64 may be provided separately from the semiconductor chip 4. In the above example, a semiconductor sensor using a magnetic sensor array is used as the magnetic sensor. However, even if a semiconductor sensor such as a vector magnetic sensor that detects the direction of the magnetic field is used. Similar effects can be obtained.

[0041] Further, in the bearing 20 with the detection device of FIG. 1, the rotation angle detection device 1 is incorporated in the roller bearing 20 so that the number of parts of the bearing-use equipment, the number of assembly steps can be reduced, and the compactness can be achieved. Can be achieved.

FIG. 17 is a block diagram showing a schematic configuration of an example of a motor rotation control device such as a servo motor or brushless motor equipped with the rotation angle detection device 1 having the above-described configuration. The motor rotation control device 70 switches the excitation current of the stator coil for rotating the motor 71 according to the rotation angle detection device 1 and the rotation angle detection value of the detection device 7 2 And a control circuit 73 that controls the rotation state of the motor by adjusting the switching timing of the excitation current. Here, the stator coil has three phases, and the driver circuit 72 switches the excitation current to the stator coils of each phase. The control circuit 73 controls the switching of the excitation current based on the rotation angle S of the motor 71 detected by the rotation angle detection device 1, and feeds back the excitation current flowing through the stator coil to control the excitation current. Lead angle control is also performed. In particular, the rotation angle detection device 1 can accurately know the position of the magnetic pole of the motor at an arbitrary time, so the excitation timing is controlled to increase the motor efficiency and keep the rotation noise low. For example, fine control according to the rotation speed and the rotation angle of the rotor is effective. In this case, the small rotation angle detection device 1 can detect the angle with high precision, and the device can be downsized and improved in performance.

FIG. 18 shows an example in which the bearing 20 with the detection device of FIG. 1 is incorporated into the shaft end of the rotating shaft 10 of the brushless motor 74. The brushless motor 7 4 has a cylindrical motor housing 7 5 closed at both ends, and is concentric with the motor housing 7 5. Rotating shaft 10 arranged in the shape of a rotor, rotor 76 provided on this rotating shaft 10, and stator provided on the inner peripheral surface of motor housing peripheral wall 7 5 a in a radial direction facing this opening 7 6 7 and 7 are provided. The rotating shaft 10 is rotatably supported at both ends of the motor housing 75 by the bearing 20 with the detection device and the other bearing 25. In this case, since the rotation angle detection device 1 is integrated with the bearing 20, it is compact and does not require assembly adjustment, reducing the number of assembly steps, and is highly convenient.

FIG. 19 shows another example in which the rotation angle detection device 1 is incorporated in the shaft end of the rotation shaft 10 of the brushless motor 74. Here, instead of attaching the sensor mounting member 4 7 to the outer ring 22 of the bearing 20, the sensor mounting member 4 7 is attached to the bearing fitting portion 7 9 formed on the motor housing end wall 7 5 b. The rotation sensor 3 A is mounted on the sensor mounting member 4 7 via the circuit board 7 8. That is, in this example, the rotation angle detection device 1 is completely separated from the bearing 20. In the bearing fitting portion 7 9, a step portion 7 9 a concentric with the shaft center O of the rotary shaft 10 is formed, and the step portion 7 9 a has the sensor mounting member 4 7 on the body 4 7 a. The rotation sensor 3 A (FIG. 1) is arranged concentrically with the rotation shaft 10 by fitting the annular convex portion 47 b provided on the back surface. The sensor mounting member 4 7 is formed by fitting the annular protrusion 4 7 b to the stepped portion 7 9 a of the bearing fitting portion 7 9 and fastening the sensor mounting member body 4 7 a with the mounting screw 40. Fixed to motor housing end wall 7 5 b. In this case, the axial position of the rotation sensor 3A relative to the bearing 20 is determined, and the axial position of the magnet 2 relative to the bearing 20 is determined when the rotating shaft 10 is fitted to the inner ring 21 of the bearing 20. With the rotary shaft 10 fitted to the inner ring 21, the axial gap (gap) between the magnet 2 and the rotation sensor 3 A can be kept within a specified range.

Next, in each of the above-described embodiments of the present invention, an application example that does not have this requirement will be described. The semiconductor chip composing the rotation sensor 3 B in this application example has almost the same configuration as the semiconductor chip of the rotation sensor 3 A shown in FIG. 12. The angle calculation process by the angle calculation means of the rotation sensor 3 A (FIG. 4) ), Output of magnetic sensor array at 3 A rotation sensor The same applies to the waveform (Fig. 5) and the timing chart (Fig. 13) of the processing operation cycle in which the rotation sensor 3A detects and outputs the rotation angle. In this application example as well, in the case of the zero cross positions X 1 and X 2 in the magnetic sensor arrays 5 B and 5 D, for example, by the rotation angle calculation process of FIGS. Based on the zero cross position data obtained from these outputs, the rotation angle 0 is calculated in the same manner as described above. FIG. 20 is a block diagram showing the circuit configuration of the rotation sensor 3B. The rotation angle 0 is calculated by the arithmetic circuit unit 6 B and output by the output cable 29 (FIG. 1) or a serial communication circuit 83 described later. That is, the magnetic data sampled by the magnetic sensor arrays 5 A to 5 D are amplified and AD converted and input to the arithmetic circuit unit 6. The angle calculation means 61 in the arithmetic circuit section 6B calculates the rotation angle 0 by performing the arithmetic processing shown in FIGS. 4 and 5 based on the sampling values by the magnetic sensor arrays 5A to 5D.

On the other hand, the rotation speed calculation means 6 2 in the arithmetic circuit section 6 B stores the data of the rotation angle 0 output from the angle calculation means 61 every time T in the memory 80 every time T, and changes the data. Calculate the rotational speed ω and rotational direction. The calculation is performed as follows.

When the sampling rotation angle 0 (η) changes every time, the rotation speed ω can be calculated from the change angle between successive samplings as shown in the following equation (6).

ω = {θ (η + 1)-θ (η)} ΖΤ …… (6)

If the rotation speed is low and the rotation angle 0 (η) does not change with each sampling, calculate the rotation speed ω as shown in the following equation (7) from the amount of angle change between several to several tens of samplings. be able to.

ω = {Θ (n + m)-θ (η)} mT …… (7) However, 0 (n + m) represents the rotation angle obtained by the (n + m) sampling.

The rotational speed ω data obtained in this way is input to an output circuit 82 which is a speed signal output means, where it is converted into a rotational speed signal in a predetermined signal form and output to the outside. The setting of the output signal form is performed by storing it in the setting memory 84, which is the setting content storage means, from the external setting means 91 provided outside the rotation sensor 3 を via the serial communication circuit 83. Is called. Configuration memory 84 has a non-volatile memory. Here, the serial communication circuit 8 3 force force provided as part of the arithmetic circuit section 6 される configured as a large-scale integrated circuit together with the magnetic sensor arrays 5 Α to 5 D on the semiconductor chip 4 Serial communication circuit 8 3 may be provided outside the semiconductor chip 4.

FIG. 21 is a block diagram showing details of the output circuit 82 in FIG. In the setting memory 84, from the external setting means 91 (Fig. 20) via the serial communication circuit 83, in addition to the output signal form, a speed upper limit set value 85 A, speed lower limit setting The value 8 5 B and the setting value of the conversion calculation method (not shown) (logarithmic conversion or linear conversion is specified) are stored, and these setting values are read out when the power is turned on. These speed upper limit set value 8 5 A, speed lower limit set value 8 5 B, output circuit (speed signal output means) 8 2 output conversion circuit 8 6 according to conversion calculation method, rotation speed calculation means 6 2 ( The rotation speed ω data given from Fig. 20 0) is converted into a rotation speed signal. The output signal may be a digital signal or an analog signal. For example, the upper limit value setting 8 5 Α corresponds the rotation speed 5 0 0 0 rpm to the voltage of 5 V, the lower limit value setting 8 5 B corresponds the stop state to the voltage of 0 V, and the value between them corresponds linearly The conversion is made.

The converted rotation speed signal is used to selectively turn on the switches 9 0 A to 90 C according to the output signal form set in the setting memory 84, voltage output circuit 8 7, current output circuit 8 8, By selecting one of the P WM output circuits 8 9, the output is switched to voltage output, current output, or P WM output and output to the outside. Example For example, when voltage output is selected, a voltage according to the rotational speed ω is output, so that it can be used in the same way as for tacho generators. In addition, when there are many noise sources in the surrounding environment of the rotation angle detection device 1, if the current output is set, a current that changes according to the rotational speed ω is output, and the signal form is less susceptible to noise. It becomes. In the P MW output, the output pulse width changes according to the rotational speed ω. In this case, since the setting memory 84 has nonvolatile memory, the setting values once set can always be used in that state.

In this application example, the rotational speed ω data is output to the outside through the serial communication circuit 8 3. Therefore, the serial communication circuit 83 forms a speed signal output means for outputting a signal of the rotational speed ω to the outside together with the output circuit 82.

As described above, the rotation angle detection device 1 with the rotation speed signal output includes the rotation speed calculation means 62 that calculates the rotation speed ω from the time change of the rotation angle 0 detected by the angle calculation means 61. Since there is a speed signal output means (output circuit) 8 2 that outputs a signal of the rotational speed ω calculated by this rotational speed calculation means 6 2, a microcomputer calculation processing circuit installed separately would be used if conventional. Information on the rotational speed ω that could not be detected without it can be output together with information on the rotation angle 0 from one rotation angle detection device 1, making it possible to provide a highly convenient detection device. Further, in this application example, the speed signal output means 82 can switch the form of the output rotational speed ω signal by setting, so that the speed signal output means 82 rotates in the output form according to the environment to be used and the connected equipment. The speed signal can be taken out and can be widely used depending on the application.

Also, since the external setting means 9 1 that enables the setting related to conversion or output of the speed signal output means 82 to be set from outside by communication is provided, the setting can be easily changed from the outside, The rotation angle detector 1 can be used for various purposes.

[0049] In addition, the rotation angle detection device 1 with the rotation speed signal output is incorporated integrally. According to the bearing with detection device 20, it is possible to reduce the number of parts, the number of assembly steps, and downsizing of the equipment using the bearing. In that case, since the rotation angle detection device 1 can detect the rotation angle 0 and the rotation speed ω, it can be used for a wide range of applications.

[Aspect 1]

A rotation angle detection device with a rotation speed signal output as aspect 1 includes a magnet having a pair of magnetic poles arranged at the end of the rotation axis of a rotating body that is rotatable with respect to a fixed member. A rotation angle detection device provided with a magnetic sensor comprising a large-scale integrated circuit on the fixed member facing the axial direction, and provided with an angle calculation means for detecting the rotation angle of the rotating body from the output of the magnetic sensor, Rotation speed calculation means for calculating the rotation speed from the time change of the rotation angle detected by the angle calculation means, and speed signal output means for outputting a signal of the rotation speed calculated by the rotation speed calculation means are provided. is there. According to this configuration, the angle calculation means detects the rotation angle of the rotating body based on the output of the magnetic sensor, and the rotation speed calculation means calculates the rotation speed from the time change of the rotation angle detected by the angle calculation means. The rotation speed signal is output by the speed signal output means. For this reason, rotation speed information that could not be detected without using an external circuit such as a separately installed microcomputer or calculation processing circuit is output together with the rotation angle information from a single rotation angle detector. Therefore, a highly convenient detection device can be obtained.

[Aspect 2]

In the first aspect, the magnetic sensor including the large-scale integrated circuit may be a magnetic sensor array. With a magnetic sensor array, small and accurate angle detection can be performed.

[Aspect 3]

In the first aspect, a serial communication circuit serving as the speed signal output means may be provided.

[Aspect 4] In Aspect 1, the speed signal output means converts the speed, which is a calculation result by the rotation speed calculation means, so as to change within a set upper limit value and lower limit value range. In this configuration, for example, the rotation speed 5 0 0 0 rpm corresponds to a voltage of 5 V by setting an upper limit value, the stop state is made to correspond to a voltage of 0 V by setting the lower limit value, and the values in between are linearly supported. It is possible to convert it.

[Aspect 5]

In the aspect 4, the speed signal output means may be configured to switch a signal conversion method of the output rotational speed between linear conversion and logarithmic conversion by setting.

[Aspect 6]

In aspect 1, the speed signal output means may be capable of switching the form of the output rotational speed signal by setting. This configuration can be used in a wide range depending on the environment used and the connected equipment.

[Aspect 7]

In the aspect 1, the speed signal output means may output at least two kinds of output of the rotational speed signal of voltage output, current output, and PWM (pulse width modulation) output. . There may be at least two of the P WM outputs. In this configuration, for example, when voltage output is selected, a voltage according to the rotation speed is output, so that it can be used in the same way as a tachometer. In addition, when there are many noise sources in the surrounding environment of the rotation angle detection device, if the current output is set, a current that changes according to the rotation speed is output, and the signal form is less susceptible to noise. In PMW output, the output pulse width changes according to the rotation speed.

[Aspect 8]

In the first aspect, an external setting unit that performs a setting related to conversion or output of the rotation speed calculating unit or the speed signal output unit from the outside by communication may be provided. “External” as used herein is external to the speed signal output means. this In the case of the configuration, since the setting related to the conversion or output of the speed signal output means can be changed from the outside by communication, it can be adapted to various applications with one rotation angle detection device.

[Aspect 9]

In Aspect 8, setting content storage means for storing the content set by the external setting means in a nonvolatile memory is provided inside or outside the large-scale integrated circuit constituting the magnetic sensor, and the setting content storage means is powered on Sometimes, the stored contents of the non-volatile memory may be read and used as the setting contents of the rotational speed calculating means or the speed signal output means. In this configuration, the contents set by the external setting means are stored in the nonvolatile memory of the setting contents storing means, so that each set value once set is always set as the setting contents of the speed signal output means in that state. Can be used.

[Aspect 1 0]

A bearing with a detection device according to aspect 10 includes the rotation angle detection device with a rotational speed signal output according to aspect 1 incorporated in the bearing. According to this configuration, it is possible to reduce the number of parts, the number of assembly steps, and the compactness of the equipment that uses the bearing. In that case, the rotation angle detector can detect the rotation angle and the rotation speed, and can be used for a wide range of applications.

As described above, the preferred embodiment of the present invention has been described with reference to the drawings. Those skilled in the art will readily consider various changes and modifications within the obvious scope by referring to the present specification. . Accordingly, such changes and modifications are to be construed as within the scope of the invention as defined by the appended claims.

Claims

The scope of the claims

[1] A magnet provided on the rotation side member and having circumferential anisotropy around the rotation center;

A magnetic sensor in which a plurality of magnetic sensor elements are arranged in a plane and opposed to the magnet in the axial direction of the rotation center of the rotation side member;

The magnetic field intensity of the magnet is measured from the output of each magnetic sensor element of the magnetic sensor, and angle calculating means for detecting the rotation angle of the rotating side member based on the measured value, and the magnetic sensor element detects the magnetic field of the magnet. A rotation time correction unit that corrects a delay time from when the angle is calculated until the detection angle is output by the angle calculation unit.

[2] The rotation detection device according to claim 1, wherein the magnet is disposed at a rotation shaft end portion of the rotation side member to form a pair of magnetic poles.

[3] In Claim 1, further, an interpolation unit that interpolates a sampling interval of the magnetic field by the magnetic sensor and calculates a change in angle, a delay time correction by the delay time correction unit, and an interpolation process by the interpolation unit And a rotation detecting device provided with output means for outputting the rotated angle.

4. The rotation detection device according to claim 1, further comprising a pulse generation circuit that generates a rotation pulse signal from the output of the magnetic sensor, wherein the output means outputs a rotation angle output as a pulse signal.

[5] The rotation detection device according to claim 4, wherein the pulse signal includes two rotation pulse signals having different 90 ° phases, or a rotation pulse signal and a rotation direction signal.

6. The rotation detection device according to claim 4, further comprising an index signal generation circuit that outputs an index signal for each rotation of the rotation side member from the output of the magnetic sensor.

7. The rotation detection device according to claim 6, further comprising storage means for storing an angle value for outputting the index signal and angle value setting means for setting the angle value for outputting the index signal.

[8] In Claim 1, the functions of the delay time correction means and the interpolation means are respectively provided. A rotation detection device provided with a function on / off means for switching between an on state and an off state.

2. The automatic switching means according to claim 1, further comprising an automatic switching means for switching between the ON state and the OFF state of the delay time correction means according to whether or not the rotation speed of the rotation side member is equal to or higher than a set speed, Rotation detector that is turned off.

The delay time correction unit according to claim 1, wherein the delay time correction unit includes: a rotation speed calculation unit that calculates a rotation speed from a time change in the rotation angle detected by the angle calculation unit; and a rotation speed calculated by the rotation speed calculation unit. A rotation angle detection device comprising angle time delay correction means for correcting a time delay of rotation angle from detection of a magnetic field by the magnetic sensor to output of a rotation angle by the angle calculation means.

The rotation angle corrected by the angle time delay correction unit according to claim 10,

—Rotation angle estimating means for estimating the rotation angle of the rotation shaft at an arbitrary time from the rotation angle information obtained at regular intervals and the rotation speed information calculated by the rotation speed calculation means. The rotation angle detection device provided with

The rotation angle detection device according to claim 10, wherein the angle calculation means, the rotation speed calculation means, and the angle time delay correction means are integrated in a large-scale integrated circuit constituting the magnetic sensor.

A bearing with a detection device, wherein the rotation angle detection device according to claim 1 is incorporated in a bearing in which a rolling element is interposed between the rotation side member and the fixed side member.

A rotation control device for a motor comprising: the rotation angle detection device according to claim 1; and a control circuit for controlling an excitation current and excitation timing of the motor by an output of the rotation angle of the rotation angle detection device.